To anyone who ever complained that politics wasn’t substantive, buckle up: the 2012 Presidential campaign just became a debate about that most substantive of all issues, the federal budget. The signature issue of Mitt Romney’s vice presidential pick, Paul Ryan, is fiscal policy: his 2008 “Road Map for America’s Future” (pdf) improbably propelled him from an unusually earnest and likeable young Congressman to national prominence and now Romney’s VP pick. The current GOP budget blueprint (pdf) that bears Ryan’s name will now be picked apart for what it would mean for the country.

Medicare, Medicaid and Social Security

The Ryan plan’s most dramatic reforms would come to federal health insurance programs. While those over 65 in 2022 would retain traditional Medicare, everyone younger would be switched to private insurance, subsidized in part by the government. This would result in higher costs or less coverage for most people under 65, who would choose between a variety of private plans, with the option of shopping for cheap, low-coverage ones, or choosing expensive high-coverage ones. The eligibility age for Medicare would gradually rise to 67, and the size of insurance subsidies would increase more slowly than the expected growth of health care costs.

Ryan’s plan would also repeal Obamacare, which is scheduled to extend mandatory, partially subsidized health coverage to 30 million Americans in 2014, and the law’s accompanying host of health insurance regulations.

Medicaid, the joint state and federal health program for the country’s 50 million poor people, would also receive dramatic changes. The Ryan plan would decentralize it by making it a block-grant program where the federal government turns over all funds to the states’ discretion. Ryan’s plan would also cut Medicaid by $750 billion over ten years, likely causing further cuts in service or spikes in cost to beneficiaries.

Ryan’s original 2008 Road Map embraced George W. Bush’s effort to partially privatize Social Security by introducing private savings accounts. Subsequent versions adopted by the broader Republican party are silent on Social Security, except to say that the government should tackle reform.

Taxes, spending and the deficit

Ryan’s plan envisions a broadening of the tax base and a lowering of individual income tax rates from a maximum of 35% at the moment, to 25%. There would be one lower tax rate of 10% for those filing jointly with income under $100,000. It would end some tax breaks and deductions to help bring in revenue, although his plan doesn’t specify which ones. The big ticket items, like mortgage interest and charitable deductions, are unlikely targets. Similarly, Ryan’s plan would reduce the top corporate tax rate from 35% to 25% and remove exemptions. His most recent budget would bring in $37 trillion in tax revenue over ten years compared to the White House’s most recent plan, which would bring a little over $40 trillion over the same period.

Ryan’s plan would spend $6.8 trillion less over ten years than the current White House budget. Those cuts come primarily from the health care programs; defense spending is untouched.

The Ryan plan’s budget deficit would be around 1% of GDP over the next ten years. It is not projected to balance the budget until 2040.

The “Other” Plans

Ryan’s most recent budget will be the most scrutinized outline for the country’s future, but it won’t be the only one. While Ryan’s original 2008 plan transmuted into a budget the whole Republican party could embrace, Democrats will highlight the oldest and most radical parts.

Thanks in part to the successful use Democrats have already made of both Ryan’s budget and his original Road Map, particularly with seniors afraid their health care is in danger, Ryan collaborated last December with Ron Wyden, the senior Democratic Senator from Oregon, on a much more moderate plan for Medicare. The Ryan-Wyden plan for Medicare would make privatized health care plans optional.Ryan was also a member of the Obama-appointed Simpson-Bowles commission, which came up with aggressive deficit and debt reduction recommendations. Ryan voted against the plan because it would have raised taxes by $2 trillion over the next ten years, boosting capital gains taxes among other measures.

How the Romney campaign manages the issue of Ryan’s Road Map will be a key element of the campaign in coming weeks. So far, in material released by the campaign today after the Ryan pick, they’re saying, “Gov. Romney applauds Paul Ryan for going in the right direction with his budget, and as President he will be putting together his own plan for cutting the deficit and putting the budget on a path to balance.”

Ryan continues staunchly to defend his vision. Once he ascended to budget chairman, he said, “I wasn’t trying to write the Republican platform, I was simply trying to do my job as head of the Budget Committee to show a workable solution for our nation’s fiscal problems and I was really trying to get a debate started,” Ryan told TIME in 2010. “If you talk to people like adults, people will listen. I really do believe that people want to be talked to like adults on this stuff because they know the thing’s broken.”